Slot antenna

Abstract

A slot antenna located on a substrate with a first surface and a second surface opposite to the first surface includes a feeding portion and a radiating portion. The feeding portion is located on the first surface of the substrate to feed electromagnetic signals. The radiating portion is located on the second surface of the substrate and defines a sector-shaped slot, a first rectangle-shaped slot, a second rectangle-shaped slot, and a third rectangle-shaped slot, wherein the sector-shaped slot is defined by a first semidiameter, a second semidiameter, and an arc connected one by one.

1. A slot antenna located on a substrate having a first surface and a second surface opposite to the first surface, the slot antenna comprising:
 a feeding portion located on the first surface of the substrate, to feed electromagnetic signals; and 
 a radiating portion located on the second surface of the substrate and defining a sector-shaped slot, a first rectangle-shaped slot, a second rectangle-shaped slot, and a third rectangle-shaped slot, wherein the sector-shaped slot is defined by a first semidiameter, a second semidiameter, and an arc connected one by one; 
 wherein the first rectangle-shaped slot, the second rectangle-shaped slot, and the third rectangle-shaped slot are commonly extended away from a center of the sector-shaped slot, and the second rectangle-shaped slot and the third rectangle-shaped slot are substantially symmetrical based on a symmetry axis of the sector-shaped slot; 
 wherein a projection of the feeding portion on the second surface of the substrate overlaps with the first rectangle-shaped slot. 
 
     
     
       2. The slot antenna as claimed in  claim 1 , wherein the symmetry axis of the sector-shaped slot and a symmetry axis of the first rectangle-shaped slot are along the same line. 
     
     
       3. The slot antenna as claimed in  claim 1 , wherein the feeding portion is perpendicular to the symmetry axis of the sector-shaped slot. 
     
     
       4. The slot antenna as claimed in  claim 1 , wherein the second rectangle-shaped slot and the third rectangle-shaped slot are in parallel with the first semidiameter and the second semidiameter, respectively. 
     
     
       5. The slot antenna as claimed in  claim 1 , wherein a central angle of the sector-shaped slot is about 90°. 
     
     
       6. The slot antenna as claimed in  claim 1 , wherein a total perimeter of the sector-shaped slot and the first rectangle-shaped slot is about a twice wavelength of a first frequency band radiated by the slot antenna. 
     
     
       7. The slot antenna as claimed in  claim 6 , wherein a length of the second rectangle-shaped slot is about a quarter of a wavelength of a second frequency band radiated by the slot antenna. 
     
     
       8. The slot antenna as claimed in  claim 7 , wherein a frequency of the second frequency band is higher than that of the first frequency band.